py3k: filter() is never False (#1602)
py3k: filter() is never False (#1602)

Former-commit-id: 3c1bc8fdbb3389cc679615ad1b923122444ae3d7
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox